The present invention relates in general to a writing instrument of the type employing a removable, refill ink container which is made and sold separately from the writing instrument and, more particularly, the present invention provides a novel washing liquid cartridge which contains a washing liquid and is adaptable to the above-described refill ink type writing instrument for washing an ink passage within the writing instrument.
Various types of ink for a writing instrument have been used and the ink can be classified into two types: one having a resin as a component and the other having no resin contained therein. The former type of ink contains a pigment and is used in, for example, a writing instrument of the type having a tubular writing tip and a needle longitudinally movably mounted within the tubular writing tip. This type of writing instrument preferably has a weight or an inertia member connected to the movable needle so as to enhance the longitudinal movement of the needle for the principal purpose of ensuring a continuous and reliable capillary action of ink from the removable ink container or ink refill towards the tubular writing tip. The latter type of ink containing no resin contains a dye and is used in a generally known fountain pen.
The ink containing a resin has many advantages but has a problem that it tends to create difficulties in successive uses of a writing instrument when the ink in the instrument is locally or entirely dried and solidified because the resin used for this type of ink is water-insoluble or difficult to dissolve in water and, thus, the instrument can not be effectively washed with water.
Therefore, a washing liquid has been made commercially available separately for an non-disposable or permanent-type writing instrument using an ink container and a resin-containing ink so as to cope with the problem of drying of the ink. When the commercially available washing liquid is used for washing the writing instrument, as shown in FIGS. 3A-3F, a cap of a washing liquid tank 2 is removed (FIG. 3A) and washing liquid 1 is poured into a cup 3 or any other suitable utensil (FIG. 3B). Thereafter, a part or parts 4 of the writing instrument to be washed is dipped into the washing liquid (FIG. 3C). When the dried and solidified ink is dissolved fully, the washing liquid 1 is discharged from the cup 3 (FIG. 3D) and then the parts 4 of the writing instrument are washed with water (FIG. 3E) and dried for a successive use (FIG. 3F). If an immediate use of the writing instrument is desired, an ultrasonic treatment can be applied when the parts 4 are dipped into the washing liquid 1 and drying is carried out by a suitable drying apparatus.
A problem with the washing procedure described above is that not only the inside of the writing instrument but also the outside thereof is extensively soiled more than is necessary by the washing liquid containing dissolved resin.